Patent GB-353948-A (GB)
Title: Improvements in and relating to automatic gas recording and regulating apparatus
IPC: G01F3/30
Filed: 1930-04-30
Abstract: 353,948. Electrically-actuated valves; components. MILLS, T. A., Laurieston, Saltburn, Yorkshire, and BOSANQUET, W. S. B., Gainford, Darlington. April 30, 1930, No. 13326. [Class 135.] Recording apparatus, applications of ; leakage, preventing.-The flow of gas in a main 12, Fig. 4, is maintained at any desired rate by means of a pressure bell connected to the main so as to be sensitive to the pressure differential across s a restriction 11 therein, the bell being balanced by a variable weight and being adjustably connected to a contactor reversing switch gear adapted to close one of two electric circuits when the bell moves, so as to open or close a valve 64 in the main. The bell 2, Fig. 1, dips into an oil seal in a casing 1, a pipe 10 being led to the underside of the bell from the high-pressure side of the restriction while a pipe 13 leads to the upper part of the casing from the low-pressure side. A rod 7 secured to the lower closed end of a tube 5 fixed to the bell passes up through a tube 4 secured to the casing 1, a mercury seal 6 being provided between the tubes. The rod is suspended from one end of a balance arm 16, Fig. 3, from the other end of which is suspended a rod 19 carrying a series of balance weights 20 adapted to be supported successively, as the bell lifts, by the steps of a stepped holder 21, the individual weights and steps being such that the movements of the bell under various pressure differentials, selected to correspond to evenly-spaced volume flows, correspond to water-gauge movements under similar pressures. Alternatively, the balance weight may dip into a liquid bath, the shape of the weight or of the bath or of both being such that the weight of liquid displaced for a given movement of the bell corresponds to the pressure causing such movement; or the balance weight may be suspended from a balanced cam on the arm 16 such that as the bell moves the weight approaches or recedes from the fulcrum of the arm. A rack 23, Fig. 1, on the rod 7 meshes with a toothed sector 33 on a pivoted lever 34 to which is connected a vertical rod 36. A sleeve 39 is secured on the latter by a screw 41, Figs. 5 and 7, in the position corresponding to the flow which it is desired to maintain in the main 12, and carries, within a switch casing 37, a contactor disc 40 arranged between two pairs of counterbalanced contactor arms 42, 42<1> and 43, 43<1>, pivotally mounted in insulated brackets 44, 47 depending from the cover 45. The setting of the arms is determined by insulated members 49, 50 carried by threaded rods 51, 54 projecting through the cover to receive adjusting nuts 52, 55. The arms are connected, through insulated terminals 59, 60 on the cover 45, to the relays 61, 61<1> of a switch. gear 62 controlling a motor 63 operating the valve 64, the connections being such that when the disc 40 contacts with the lower arms 43, 43<1>, due to an increase in flow in the main, the motor 63 operates to close the valve 64, whiie when the disc contacts with the upper arms the motor operates to open the valve. A second rack 22, Fig. 1, on the rod 7 meshes with a toothed sector 24 on a pivoted lever 25 formed with a cam surface 28 engaged by a roller 32 on a counterbalanced triangular frame 29 pivoted eccentrically of the lever 25 and carrying a pen 30 co-operating with a recording drum 31, the arrangement being such that the movements of the pen are porportional to the square root of the movements of the bell and thus to the volume. flow in the main.